let test = 666;
; (function (window, undefined) {

  function init(el) {
    let els = document.querySelectorAll(el)
    for (let i = 0; i < els.length; i++) {
      this[i] = els[i]
    }

    this.length = els.length
  }

  let jQuery = function (el) {
    return new init(el)
  }
  jQuery.extend = function (object) {
    for (let key in object) {
      init.prototype[key] = object[key]
    }
  }
  init.prototype = {
    css(cssAttr, cssVal) {
      for (let i = 0; i < this.length; i++) {
        this[i].style[cssAttr] = cssVal 
      }

      return this
    },
    ajax(options) { },
    attr(options) { },
    addClass(options) { },
  }


  window.jQuery = window.$ = jQuery
})(window)

$.extend({
  bg() {

  }
})
